1. Field of the Invention
The present invention relates to vehicular lighting devices employed in automobiles or the like.
2. Description of the Related Art
Halogen lamps and high intensity discharge (HID) lamps have been mainstream as vehicle lighting devices, particularly, headlamp light sources, to date, but in recent years, the development of vehicle lighting devices employing semiconductor light sources such as light-emitting diodes (LEDs) as an alternative to these devices has been advancing. For the sake of further improvement in visibility, vehicle lighting devices furnished with laser diodes (also referred to as “semiconductor lasers”) and phosphors instead of LEDs have been disclosed (reference is made to Patent Document 1, for example). With the technology described in Patent Document 1, ultraviolet light that is excitation light output from a laser diode is shone onto a phosphor. Receiving the ultraviolet light, the phosphor generates white light. The white light generated by the phosphor is beamed frontward of the lighting device, whereby a predetermined light distribution pattern is formed. With the technology described in Patent Document 1, the excitation light is beamed.